/******************************************************
The lowest-level memory management

(c) 1994, 1995 Innobase Oy

Created 6/9/1994 Heikki Tuuri
*******************************************************/

#ifndef mem0pool_h
#define mem0pool_h

#include "univ.i"
#include "os0file.h"
#include "ut0lst.h"

typedef struct mem_area_struct mem_area_t;
typedef struct mem_pool_struct mem_pool_t;

/* The common memory pool */
extern mem_pool_t *mem_comm_pool;

/* Memory area header */

struct mem_area_struct
{
  ulint size_and_free; /* memory area size is obtained by
                       anding with ~MEM_AREA_FREE; area in
                       a free list if ANDing with
                       MEM_AREA_FREE results in nonzero */
  UT_LIST_NODE_T(mem_area_t)
  free_list; /* free list node */
};

/* Each memory area takes this many extra bytes for control information */
#define MEM_AREA_EXTRA_SIZE (ut_calc_align(sizeof(struct mem_area_struct), UNIV_MEM_ALIGNMENT))

/************************************************************************
Creates a memory pool. */

mem_pool_t *mem_pool_create(
    /*============*/
    /* out: memory pool */
    ulint size); /* in: pool size in bytes */
/************************************************************************
Allocates memory from a pool. NOTE: This low-level function should only be
used in mem0mem.*! */

void *mem_area_alloc(
    /*===========*/
    /* out, own: allocated memory buffer */
    ulint size,        /* in: allocated size in bytes; for optimum
                       space usage, the size should be a power of 2
                       minus MEM_AREA_EXTRA_SIZE */
    mem_pool_t *pool); /* in: memory pool */
/************************************************************************
Frees memory to a pool. */

void mem_area_free(
    /*==========*/
    void *ptr,         /* in, own: pointer to allocated memory
                       buffer */
    mem_pool_t *pool); /* in: memory pool */
/************************************************************************
Returns the amount of reserved memory. */

ulint mem_pool_get_reserved(
    /*==================*/
    /* out: reserved mmeory in bytes */
    mem_pool_t *pool); /* in: memory pool */
/************************************************************************
Reserves the mem pool mutex. */

void mem_pool_mutex_enter(void);
/*======================*/
/************************************************************************
Releases the mem pool mutex. */

void mem_pool_mutex_exit(void);
/*=====================*/
/************************************************************************
Validates a memory pool. */

ibool mem_pool_validate(
    /*==============*/
    /* out: TRUE if ok */
    mem_pool_t *pool); /* in: memory pool */
/************************************************************************
Prints info of a memory pool. */

void mem_pool_print_info(
    /*================*/
    FILE *outfile,     /* in: output file to write to */
    mem_pool_t *pool); /* in: memory pool */

#ifndef UNIV_NONINL
#include "mem0pool.ic"
#endif

#endif
